POST HARVEST CONTROL OF AFLATOXIN PRODUCTION ON IN-SHELL MOIST PEANUTS BY SODIUM ORTHO-PHENYLPHENATE .2. HARVESTER TESTS

This work was carried out to optimize a spaying method for the applica tion of sodium ortho-phenylphenate (SOP) solution on in-shell moist pe anuts during crop gathering with a combine harvester, aiming at contro l of aflatoxin production. In a previous work, it was verified that th e SOP spraying operation under field conditions did not attain total p od coverage, indicating the need for its optimization. In the present work, SOP spraying was carried out during mechanical harvesting of the 1988 rainy season peanut crop. The spraying attachment was adapted to a combine harvester and a 0.5% SOP solution used. Despite the improve ments made for SOP application, technical problems were still encouter ed, such as the accumulation of peanuts inside the bag filler pipe whi ch hampered spraying efficiency. Both treated and control lots showed an increase in initial aflatoxin levels during storage. High aflatoxin contamination of treated samples may have occurred due to the still t echnically inadequate coupling of the spraying attachment to the harve ster and/or to a suboptimal SOP concentration used for the chemical co ntrol of aflatoxin.